Loose front sight insert - question

[gunsrfun1]

Hello - The front sight insert on my 1920 commercial is loose, and I am curious how to resolve it. When I say loose, I do not mean falling-out loose. Rather, I can push the insert left and right with my finger, but it will stay in position until I fire it, and then it does tend to drift one way or the other over time. For obvious reasons, I do not want to peen the insert or the base. I thought about buying a spare insert that I could peen, and I guess that is still an option if I can find one at a reasonable price. Another option is to clean the surfaces of the base and insert with Gunscrubber, and then apply a drop of blue Loctite. Seems like a simple and hopefully effective idea. Does this sound like a reasonable solution? If not, I am open to suggestions. thanks